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Arene C-H Iodination Using Aryl Iodides
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作者 Shangda Li Chunhui Zhang +5 位作者 Lei Fu Hang Wang Lei Cai Xiaoxi Chen Xinchao Wang Gang Li 《CCS Chemistry》 CAS 2022年第6期1889-1900,共12页
Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extreme... Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extremely rare.Herein,we report the first Pd(Ⅱ)-catalyzed C-H iodination of arenes using 2-nitrophenyl iodides as the mild iodinating reagents via a formal metathesis reaction.Unusual C-I bond formation occurred with aryl iodides in preference to competing C-C coupling in this reaction.Assisted by aliphatic carboxyl directing groups,a range of hydrocinnamic acids and related arenes could be selectively iodinated at either meta-or orthopositions of the phenyl ring.Remote diastereoselective C-H activation was also promising.This method might unfold a novel approach to iodinate challenging substrates. 展开更多
关键词 formal metathesis c-h iodination aryl iodide site-selective carboxyl directing group
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非血红素铁酶中动态配位变化对C-H键选择性胺化反应的调控机制
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作者 张璇 刘佳 +2 位作者 廖浪星 王子宽 王斌举 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第7期131-144,共14页
氮杂环丙烷结构广泛存在于天然生物碱中,具有杀菌、抗癌等作用.然而,目前关于生物体系在合成氮杂环丙烷结构过程中如何克服氮杂环丙烷高环张力带来的热力学不利因素,以及如何避免形成热力学更稳定的羟基化副产物的报道较少.TqaL_(NC)酶... 氮杂环丙烷结构广泛存在于天然生物碱中,具有杀菌、抗癌等作用.然而,目前关于生物体系在合成氮杂环丙烷结构过程中如何克服氮杂环丙烷高环张力带来的热力学不利因素,以及如何避免形成热力学更稳定的羟基化副产物的报道较少.TqaL_(NC)酶是目前非血红素酶家族中唯一一种能够依赖α-酮戊二酸活化C-H键,进而生成氮杂环丙烷结构的酶.深入探究TqaL_(NC)酶选择性生成氮杂环丙烷结构并避免羟基化副产物的机制,有助于深入理解非血红素铁酶家族在C-H键活化及官能化过程中的选择性调控机理.本文以TqaL_(NC)酶的晶体结构为基础,采用分子动力学(MD)模拟以及量子力学-分子力学(QM/MM)等多尺度模拟方法对TqaL_(NC)酶与L-缬氨酸(L-Val)、TqaL_(NC)酶与L-异亮氨酸(L-Ile)和F345A-TqaL_(NC)酶与L-异亮氨酸(L-Ile)三个反应过程进行了详细的机理研究.结果表明,TqaL_(NC)酶在反应过程中生成的直立式构象的Fe(Ⅳ)=O物种会通过构象异构化获得赤道面式构象,为底物(L-Val、L-Ile、L-homoalaine)上NH_(3)^(+)与Fe的配位提供结构基础.在水和关键酸性残基的介导下,底物NH_(3)^(+)两次脱去质子与Fe(Ⅳ)=O物种配位,生成HN-Fe(Ⅳ)=O结构.随后,Fe(Ⅳ)=O物种攫取底物H原子,生成HN-Fe(Ⅲ)-OH中间体.此时NH回弹反应比传统的OH回弹反应在动力学上更有优势,因此选择性地生成了氮杂环丙烷产物.在反应过程中,底物侧链与周围氨基酸的位阻效应是影响NH回弹反应能垒的重要因素.通过改变底物侧链大小(L-Val→L-Ile)以及附近氨基酸的突变(F345A)实验,证实了该结论.本文还通过理论计算预测了TqaL_(NC)酶与L-高丙氨酸的反应产物为羟基化产物,并通过新的实验证据进一步支持了理论预测的机理.此外,在HN-Fe(Ⅲ)-OH结构中,通过前线轨道理论分析发现,dπ*Fe-N,dπ*Fe-OH轨道的能量差是影响NH/OH回弹反应能垒的另一重要因素.当底物NH与Fe配位时,其配位作用能够使得dπ*Fe-N以及dπ*Fe-OH轨道有效分裂,这种分裂进而影响了反应路径的选择性,确保氮杂环丙烷产物的生成.综上,本文提出了依赖α-酮戊二酸酶催化合成氮杂环丙烷结构的新机理.研究发现,Fe中心的动态配位效应在实现C-H键选择性胺化反应并避免C-H键羟基化反应中起到了关键作用.该理论为非血红素Fe酶催化的非羟基化反应提供了新的见解,并为探索包括C-N/C-S/C-O等重要生物合成反应新机理的探究提供了新思路. 展开更多
关键词 联合量子力学-分子力学方法 c-h键活化 非血红素酶 胺化反应 羟基化反应
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Lugol's iodine增强Micro-CT成像评估口腔鳞状细胞癌切缘状态的研究
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作者 郁佳鑫 刘鲲宇 +4 位作者 章茜 蒲玉梅 胡勤刚 夏成万 王育新 《口腔医学研究》 CAS CSCD 北大核心 2024年第9期797-802,共6页
目的:本研究拟使用Lugol's iodine增强Micro-CT成像三维评估口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)切缘状态。方法:本研究共收集68例人OSCC组织样本,所有样本经3%Lugol's iodine染色12 h后行Micro-CT扫描(层厚为50... 目的:本研究拟使用Lugol's iodine增强Micro-CT成像三维评估口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)切缘状态。方法:本研究共收集68例人OSCC组织样本,所有样本经3%Lugol's iodine染色12 h后行Micro-CT扫描(层厚为50μm)。随后将经Lugol's iodine染色后的样品行常规苏木精-伊红(hematoxylin-eosin,HE)染色切片(厚度为4μm),制作数字化病理切片。分别测量影像图像和病理图像的黏膜切缘(mucosal margin,MM)和深部切缘(deep margin,DM)。结果:Lugol's iodine增强Micro-CT成像可以在三维空间中清晰区分肿瘤边界,且Micro-CT成像相较于二维病理切片,可以更准确地测量MM和DM,发现阳性切缘及临界切缘。结论:Lugol's iodine增强Micro-CT成像可以全面评估OSCC切缘,提供更全面、更清晰的肿瘤边缘信息,指导临床治疗方案选择和预后评估。 展开更多
关键词 口腔鳞状细胞癌 显微计算机断层成像 卢戈氏碘液 三维
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Whole-volume histogram analysis of spectral-computed tomography iodine maps characterizes HER2 expression in gastric cancer
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作者 Wei-Ling Zhang Jing Sun +8 位作者 Rong-Fang Huang Yi Zeng Shu Chen Xiao-Peng Wang Jin-Hu Chen Yun-Bin Chen Chun-Su Zhu Zai-Sheng Ye You-Ping Xiao 《World Journal of Gastroenterology》 SCIE CAS 2024年第38期4211-4220,共10页
BACKGROUND Although surgery remains the primary treatment for gastric cancer(GC),the identification of effective alternative treatments for individuals for whom surgery is unsuitable holds significance.HER2 overexpres... BACKGROUND Although surgery remains the primary treatment for gastric cancer(GC),the identification of effective alternative treatments for individuals for whom surgery is unsuitable holds significance.HER2 overexpression occurs in approximately 15%-20%of advanced GC cases,directly affecting treatment-related decisions.Spectral-computed tomography(sCT)enables the quantification of material compositions,and sCT iodine concentration parameters have been demonstrated to be useful for the diagnosis of GC and prediction of its invasion depth,angioge-nesis,and response to systemic chemotherapy.No existing report describes the prediction of GC HER2 status through histogram analysis based on sCT iodine maps(IMs).AIM To investigate whether whole-volume histogram analysis of sCT IMs enables the prediction of the GC HER2 status.METHODS This study was performed with data from 101 patients with pathologically confirmed GC who underwent preoperative sCT examinations.Nineteen parameters were extracted via sCT IM histogram analysis:The minimum,maximum,mean,standard deviation,variance,coefficient of variation,skewness,kurtosis,entropy,percentiles(1st,5th,10th,25th,50th,75th,90th,95th,and 99th),and lesion volume.Spearman correlations of the parameters with the HER2 status and clinicopathological parameters were assessed.Receiver operating characteristic curves were used to evaluate the parameters’diagnostic performance.RESULTS Values for the histogram parameters of the maximum,mean,standard deviation,variance,entropy,and percentiles were significantly lower in the HER2+group than in the HER2–group(all P<0.05).The GC differentiation and Lauren classification correlated significantly with the HER2 status of tumor tissue(P=0.001 and 0.023,respectively).The 99th percentile had the largest area under the curve for GC HER2 status identification(0.740),with 76.2%,sensitivity,65.0%specificity,and 67.3%accuracy.All sCT IM histogram parameters correlated positively with the GC HER2 status(r=0.237-0.337,P=0.001-0.017).CONCLUSION Whole-lesion histogram parameters derived from sCT IM analysis,and especially the 99th percentile,can serve as imaging biomarkers of HER2 overexpression in GC. 展开更多
关键词 Gastric cancer Spectral computed tomography iodine map Histogram analysis
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Performance investigation of a low-power Hall thruster fed on iodine propellant
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作者 徐宗琦 王平阳 +2 位作者 蔡东升 谭睿 姜文静 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第6期140-148,共9页
The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive,and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost,extensive availability,... The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive,and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost,extensive availability, low vapor pressure, and ionization potential. The performance of a lowpower iodine-fed Hall thruster matched with a xenon-fed cathode is investigated across a broad range of operation conditions. Regulation of the iodine vapor's mass flow rates is stably achieved by using a temperature control method of the iodine reservoir. The thrust measurements are finished utilizing a thrust target during the tests. Results show that thrust and anode-specific impulse increase approximately linearly with the increasing iodine mass flow rate.At the nominal power of 200 W class, iodine mass flow rates are 0.62 and 0.93 mg/s, thrusts are7.19 and 7.58 m N, anode specific impulses are 1184 and 826 s, anode efficiencies are 20.8%and 14.5%, and thrust to power ratios are 35.9 and 37.9 m N/k W under the conditions of 250 V,0.8 A and 200 V, 1.0 A, respectively. The operating characteristics of iodine-fed Hall thruster are analyzed in different states. Further work on the measurements of plasma characteristics and experimental optimization will be carried out. 展开更多
关键词 electric propulsion Hall thruster iodine propellant thrust measurement operating characteristics
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Iodine Nutrition, Thyroid-stimulating Hormone, and Related Factors of Postpartum Women from three Different Areas in China: A Cross-sectional Survey
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作者 SHAN Xiao Yun ZOU Yan +10 位作者 HUANG Li Chun JIANG Shan ZHOU Wei Wen QIN Qiu Lan LIU Chang Qing LUO Xiao Yan LU Jia Xi MAO De Qian LI Min YANG Zhen Yu YANG Li Chen 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第3期254-265,共12页
Objective Studies on the relationship between iodine,vitamin A(VA),and vitamin D(VD)and thyroid function are limited.This study aimed to analyze iodine and thyroid-stimulating hormone(TSH)status and their possible rel... Objective Studies on the relationship between iodine,vitamin A(VA),and vitamin D(VD)and thyroid function are limited.This study aimed to analyze iodine and thyroid-stimulating hormone(TSH)status and their possible relationships with VA,VD,and other factors in postpartum women.Methods A total of 1,311 mothers(896 lactating and 415 non-lactating)from Hebei,Zhejiang,and Guangxi provinces were included in this study.The urinary iodine concentration(UIC),TSH,VA,and VD were measured.Results The median UIC of total and lactating participants were 142.00µg/L and 139.95µg/L,respectively.The median TSH,VA,and VD levels in all the participants were 1.89 mIU/L,0.44μg/mL,and 24.04 ng/mL,respectively.No differences in the UIC were found between lactating and non-lactating mothers.UIC and TSH levels were significantly different among the three provinces.The rural UIC was higher than the urban UIC.Obese mothers had a higher UIC and a higher prevalence of excessive TSH.Higher UICs and TSHs levels were observed in both the VD deficiency and insufficiency groups than in the VD-sufficient group.After adjustment,no linear correlation was observed between UIC and VA/VD.No interaction was found between vitamins A/D and UIC on TSH levels.Conclusion The mothers in the present study had no iodine deficiency.Region,area type,BMI,and VD may be related to the iodine status or TSH levels. 展开更多
关键词 Median urinary iodine concentration Thyroid-stimulating hormone Vitamin A Vitamin D Postpartum women
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Ambulatory Radio Iodine Therapy in the Management of Hyperthyroidism in Africa: African Systematic Review and Perspectives in Burkina Faso
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作者 Ki Thierry Romuald Mamadou Salif Djigo +3 位作者 Gora Thiaw Arsène Sanou Mamounata Zoungrana Mamadou Mbodj 《Open Journal of Biophysics》 2024年第1期1-10,共10页
Introduction: In hyperthyroidism, selective irradiation of the thyroid gland with radioactive iodine is a radical treatment and an alternative to surgery. The aim of this review is to assess the medium-term efficacy o... Introduction: In hyperthyroidism, selective irradiation of the thyroid gland with radioactive iodine is a radical treatment and an alternative to surgery. The aim of this review is to assess the medium-term efficacy of outpatient treatment of hyperthyroidism with iodine-131 in Africa. Methods: We identified the studies carried out in Africa on outpatient radiation therapy between 2016 and 2020. For each article included, we noted the country concerned and the year of publication, the numbers studied, the socio-demographic characteristics of the patients, the indications for radio iodine therapy, the dose administered, the results of the hormonal dosage 6 months after radiation. Results: 13 retrospective studies were included to constitute a total population of 925 patients. The average age was 40.77 years, the sex ratio of 1/5.4 with a clear female predominance. The 3 main etiologies of hyperthyroidism justifying outpatient radio iodine therapy were Graves’ disease (55.89%), toxic multinodular goiter (22.70%) and toxic adenoma (21.40%). The average dose of iodine 131 administered per course is 13.7 mCi. No short-and medium-term complications were reported. The radio iodine therapy was effective in 86.08% (n = 796) of the patients with extremes of 72% and 100%. Conclusion: Radio iodine therapy is effective in Africa. It is simple, inexpensive on an outpatient basis and well tolerated. The introduction of outpatient radio iodine therapy could improve the management of patients with hyperthyroidism in Burkina Faso. 展开更多
关键词 HYPERTHYROIDISM Outpatient Radio iodine Therapy AFRICA
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Enriching Iodine and Regulating Grain Aroma,Appearance Quality,and Yield in Aromatic Rice by Foliar Application of Sodium Iodide
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作者 HONG Weiyuan DUAN Meiyang +5 位作者 WANG Yifei CHEN Yongjian MO Zhaowen QI Jianying PAN Shenggang TANG Xiangru 《Rice science》 SCIE CSCD 2024年第3期328-342,I0046-I0054,共24页
Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing se... Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing seasons of 2021 and 2022 to evaluate the impacts of foliar application of iodine fertilizer on aromatic rice and to explore the optimal iodine fertilizer concentration.At the full heading stage,six different concentrations of sodium iodide solutions of 0%(CK),0.010%(T1),0.025%(T2),0.050%(T3),0.075%(T4),and 0.100%(T5)were applied to indica aromatic rice cultivars Meixiangzhan 2 and Xiangyaxiangzhan.The results showed that sodium iodide treatments significantly increased the iodine and sodium contents in both leaves and grains.Compared with the CK,the T1 and T2 treatments increased the 2-acetyl-1-pyrroline(2-AP)content in mature grains by 8.41%-101.66%and 13.58%-74.60%,respectively.Improvements in the contents of 1-pyrroline-5-carboxylic acid,proline,1-pyrroline,and methylglyoxal,as well as the activity of proline dehydrogenase were also detected.Additionally,sodium iodide treatments remarkably decreased the chalky grain rate,chalkiness area,and chalkiness degree of aromatic rice,with the T2 treatment exhibiting a 17.79%-47.42%decrease in chalkiness degree compared with the CK.Meanwhile,T1 and T2 treatments showed beneficial impacts on chlorophyll content,photosynthetic characteristics,and yield components,while T3,T4,and T5 treatments exhibited adverse effects on leaf and grain yields.The linear discriminant analysis revealed significant differences between treatments.The correlation analysis and piecewise structural equation modeling showed that the iodine and sodium influenced the photosynthetic characteristics and chlorophyll content of the leaves,thereby regulating the 2-AP biosynthesis and yield components,ultimately affecting the 2-AP content and yield.Overall,this study suggests that foliar application of 0.025%sodium iodide is an effective method to enrich the iodine content in rice grains,improve the grain aroma and appearance quality of aromatic rice,without detrimental effects on grain yield. 展开更多
关键词 2-acetyl-1-pyrroline appearance quality aromatic rice foliar application grain yield iodinE
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DNA Methylation of KLRC1 and KLRC3 in Autoimmune Thyroiditis:Perspective of Different Water Iodine Exposure
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作者 Yao Chen Jinjin Liu +6 位作者 Mengying Qu Bingxuan Ren Huaiyong Wu Li Zhang Zheng Zhou Lixiang Liu Hongmei Shen 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第9期1044-1055,共12页
Objective This study aimed to identify differentially methylated genes(DMGs) associated with natural killer cells in patients with autoimmune thyroiditis(AIT), focusing on the influence of varying water iodine exposur... Objective This study aimed to identify differentially methylated genes(DMGs) associated with natural killer cells in patients with autoimmune thyroiditis(AIT), focusing on the influence of varying water iodine exposure levels.Methods Participants were divided into categories based on median water iodine(MWI)concentrations: iodine-fortified areas(IFA, MWI < 10 μg/L), iodine-adequate areas(IAA, 40 ≤ MWI ≤ 100μg/L), and iodine-excessive areas(IEA, MWI > 300 μg/L). A total of 176 matched AIT cases and controls were recruited and divided into 89, 40, and 47 pairs for IFA, IAA, and IEA, respectively. DMGs were identified using 850K Bead Chip analysis for 10/10 paired samples. Validation of DNA methylation and m RNA expression levels of the DMGs was conducted using Methyl Target^(TM) and QRT-PCR for 176/176paired samples.Results KLRC1, KLRC3, and SH2D1B were identified as significant DMGs. Validation revealed that KLRC1 was hypomethylated and highly expressed, whereas KLRC3 was hypermethylated and highly expressed in individuals with AIT. Furthermore, KLRC1 was hypomethylated and highly expressed in both IFA and IEA.Conclusion The DNA methylation status of KLRC1 and KLRC3 may play crucial roles in AIT pathogenesis. Additionally, DNA methylation of KLRC1 seems to be influenced by different iodine concentrations in water. 展开更多
关键词 Autoimmune thyroiditis DNA methylation KLRC1 KLRC3 SH2D1B iodinE
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Interpenetrating network-reinforced gel polymer electrolyte for ultra-stable lithium−iodine batteries
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作者 Ying Jiang Peng Huang +5 位作者 Minman Tong Bingxin Qi Tao Sun Zhongyun Xian Wen Yan Chao Lai 《Carbon Energy》 SCIE EI CAS CSCD 2024年第6期234-247,共14页
Li-I_(2) batteries have attracted much interest due to their high capacity,exceptional rate performance,and low cost.Even so,the problems of unstable Li anode/electrolyte interface and severe polyiodide shuttle in Li-... Li-I_(2) batteries have attracted much interest due to their high capacity,exceptional rate performance,and low cost.Even so,the problems of unstable Li anode/electrolyte interface and severe polyiodide shuttle in Li-I_(2) batteries need to be tackled.Herein,the interfacial reactions on the Li anode and I_(2) cathode have been effectively optimized by employing a well-designed gel polymer electrolyte strengthened by cross-linked Ti-O/Si-O(GPETS).The interpenetrating network-reinforced GPETS with high ionic conductivity(1.88×10^(-3)S cm^(-1)at 25℃)and high mechanical strength endows uniform Li deposition/stripping over 1800 h(at 1.0mA cm^(-2),with a plating capacity of 3.0mAh cm^(-2)).Moreover,the GPETS abundant in surface hydroxyls is capable of capturing soluble polyiodides at the interface and accelerating their conversion kinetics,thus synergistically mitigating the shuttle effect.Benefiting from these properties,the use of GPETS results in a high capacity of 207 mAh g^(-1)(1 C)and an ultra-low fading rate of 0.013%per cycle over 2000 cycles(5 C).The current study provides new insights into advanced electrolytes for Li-I_(2) batteries. 展开更多
关键词 electrode/electrolyte interface gel polymer electrolytes lithium dendrites lithium−iodine batteries polyiodide shuttle
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Iodine 131 Treatment in Graves’ Disease in a West African Country: Preliminary Study about 25 Cases in Senegal
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作者 El Hadji Amadou Lamine Bathily Serigne Moussa Badiane +14 位作者 Mamoudou Salif Djigo Gora Thiaw Kalidou Gueye Ousseynou Diop Boucar Ndong Kokou Fofo Toussaint Adambounou Alphonse Rodrigue Djiboune Papa Mady Sy Mamadou Soumbounou Mohamed Chekhma Louis Augustin Diaga Diouf Gora Mbaye Omar Ndoye Mounibé Diarra Mamadou Mbodj 《Open Journal of Biophysics》 2024年第1期56-72,共17页
Introduction: Graves’ disease is the most common cause of hyperthyroidism. Its treatment uses synthetic antithyroid drugs but the use of aggressive radical therapy such as surgery or non-aggressive therapy such as io... Introduction: Graves’ disease is the most common cause of hyperthyroidism. Its treatment uses synthetic antithyroid drugs but the use of aggressive radical therapy such as surgery or non-aggressive therapy such as iodine-131 is not uncommon. Treatment of Graves’ disease with radioactive iodine or iratherapy is a simple, inexpensive, well-tolerated treatment. It was introduced in Senegal in 2016. We report through this work the preliminary assessment of the only nuclear medicine service in Senegal in the management of Graves’ disease by iodine-131. Patients and Methods: Retrospective study of the first cases of Graves’ disease treated with iratherapy in Senegal. Socio-demographic, clinical, paraclinical, therapeutic and evolutionary aspects were studied. Radiation protection rules have been implemented and contraception has been effective for six months in women of childbearing age. Results: 25 patients were collected with a mean age of 45 years, twenty women (80%), a family goiter in 24% and a psycho-affective context in 64% of cases. Thyrotoxicosis syndrome was associated with goiter in 68% of patients and exophthalmos in 64%. Thyroid ultrasound performed in 20 patients showed vascular goiter in 80% and thyroid scintigraphy in 3 patients, homogeneous and diffuse hyperfixation. TRAK dosed in 8 patients was still positive. All patients had received first-line medical treatment. The average duration of this treatment was more than 18 months in 92%. The empirically used iodine-131 activity averaged 15.35 mCi. Oral corticosteroid therapy was prescribed in 7 patients for the prevention of malignant orbitopathy. No early side effects were noted. The remission rate at 3 months was 52% and at 6 months was 88% to 92%. Conclusion: The effectiveness of radioactive iodine, in particular ablative doses in the treatment of hyperthyroidism, is no longer to be demonstrated. Taking into account our socioeconomic context, iratherapy should be a treatment of choice for hyperthyroidism with a good quality/price ratio and excellent tolerance. 展开更多
关键词 Graves’ Disease Iratherapy iodinE-131 Senegal
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A simple and efficient method for solvent-free iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid by grinding method 被引量:3
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作者 Archana Vibhute Shyam Mokle +2 位作者 Khushal Karamunge Vasant Gurav Yeshwant Vibhute 《Chinese Chemical Letters》 SCIE CAS CSCD 2010年第8期914-918,共5页
Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides sever... Green,mild and efficient iodination of hydroxylated aromatic aldehydes and ketones using iodine and iodic acid in the solidstate by grinding under solvent-free conditions at room temperature.This method provides several advantages such as environmentally friendly,short reaction times,high yields,non-hazardous and simple work-up procedure. 展开更多
关键词 iodination Aromatic aldehydes Aromatic ketones GRINDING
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A mild,efficient and selective iodination of aromatic compounds using iodine and 1,4-bis(triphenylphosphonium)-2-butene peroxodisulfate 被引量:1
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作者 Rashid Badri Maryam Gorjizadeh 《Chinese Chemical Letters》 SCIE CAS CSCD 2009年第12期1439-1443,共5页
A simple and efficient method for the iodination of aromatic compounds has been achieved in the presence of iodine and 1,4- bis(triphenylphosphonium)-2-butene peroxodisulfate.
关键词 Iodoaromafic compounds Aromatic compounds iodinE 1 4-Bis(triphenylphosphonium)-2-butene peroxodisulfate
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单原子合金对烷基C-H键活化调控的理论研究 被引量:1
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作者 乔聪聪 傅钢 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2023年第4期427-433,I0035,共8页
单原子合金是指活性金属原子分散在Cu、Ag或Au载体上所构成的催化剂,近年来已成为单原子催化研究中的一颗“新星”.单原子合金上孤立活性位点与载体金属的电子结构不同,具有奇异的电子结构,故通常表现出独特的催化行为。目前尚缺乏一种... 单原子合金是指活性金属原子分散在Cu、Ag或Au载体上所构成的催化剂,近年来已成为单原子催化研究中的一颗“新星”.单原子合金上孤立活性位点与载体金属的电子结构不同,具有奇异的电子结构,故通常表现出独特的催化行为。目前尚缺乏一种可靠的单原子合金催化特性描述符.本文系统地考察了甲烷、丙烷和乙苯在15种Rh、Ir、Ni、Pd和Pt掺杂Cu(111)、Ag(111)和Au(111)单原子合金上初始C-H键活化.密度泛函计算表明,烷基C-H键的活化能垒与d带中心和H原子吸附相关较差,而与反应能之间相关性较好.理论分析表明,C原子在顶位的吸附与C-H活化过渡态之间存在着轨道相互作用的相似性,不仅涉及到对d,2轨道给予,也涉及day/dy≥轨道的元反馈.据此,C原子吸附能与甲烷、丙烷和乙苯C-H键活化能也具有很强的相关性(R2>0.9). 展开更多
关键词 单原子合金 c-h键活化 d带中心 热化学描述符 线性比例关系
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Aqueous Zinc Batteries with Ultra‑Fast Redox Kinetics and High Iodine Utilization Enabled by Iron Single Atom Catalysts 被引量:6
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作者 Xueya Yang Huiqing Fan +3 位作者 Fulong Hu Shengmei Chen Kang Yan Longtao Ma 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第8期368-380,共13页
Rechargeable aqueous zinc iodine(ZnǀǀI_(2))batteries have been promising energy storage technologies due to low-cost position and constitutional safety of zinc anode,iodine cathode and aqueous electrolytes.Whereas,on ... Rechargeable aqueous zinc iodine(ZnǀǀI_(2))batteries have been promising energy storage technologies due to low-cost position and constitutional safety of zinc anode,iodine cathode and aqueous electrolytes.Whereas,on one hand,the low-fraction utilization of electrochemically inert host causes severe shuttle of soluble polyiodides,deficient iodine utilization and sluggish reaction kinetics.On the other hand,the usage of high mass polar electrocatalysts occupies mass and volume of electrode materials and sacrifices device-level energy density.Here,we propose a“confinement-catalysis”host composed of Fe single atom catalyst embedding inside ordered mesoporous carbon host,which can effectively confine and catalytically convert I_(2)/I^(−)couple and polyiodide intermediates.Consequently,the cathode enables the high capacity of 188.2 mAh g^(−1)at 0.3 A g^(−1),excellent rate capability with a capacity of 139.6 mAh g^(−1)delivered at high current density of 15 A g^(−1)and ultra-long cyclic stability over 50,000 cycles with 80.5%initial capacity retained under high iodine loading of 76.72 wt%.Furthermore,the electrocatalytic host can also accelerate the I^(+)↔I_(2)conversion.The greatly improved electrochemical performance originates from the modulation of physicochemical confinement and the decrease of energy barrier for reversible I−/I_(2)and I_(2)/I^(+)couples,and polyiodide intermediates conversions. 展开更多
关键词 Aqueous zinc batteries iodine reduction reaction Fe single atom catalysts
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Relationship between Dining Place, Iodine Source, and Iodine Nutrition in School-Age Children: A Cross-Sectional Study in China 被引量:1
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作者 QIAN Ting Ting SUN Rong +10 位作者 LIU Lan Chun CHE Wen Jing ZHAO Meng ZHANG Ling LI Wei Dong JIA Qing Zhen WANG Jian Hui LI Jin Shu CHEN Zhi Hui ZHANG Bi Yun LIU Peng 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2023年第1期10-23,共14页
Objective This study assesses the impact of iodine-rich processed foods and dining places on the iodine nutritional status of children.Methods School-aged children(SAC) in seven provinces in China were selected by sch... Objective This study assesses the impact of iodine-rich processed foods and dining places on the iodine nutritional status of children.Methods School-aged children(SAC) in seven provinces in China were selected by school-based multistage sampling. Urinary iodine, salt iodine, and thyroid volume(TVOL) were determined. Questionnaires were used to investigate dining places and iodine-rich processed foods. The water iodine was from the2017 national survey. Multi-factor regression analysis was used to find correlations between variables.Results Children ate 78.7% of their meals at home, 15.1% at school canteens, and 6.1% at other places.The percentage of daily iodine intake from water, iodized salt, iodine-rich processed foods, and cooked food were 1.0%, 79.2%, 1.5%, and 18.4%, respectively. The salt iodine was correlated with the urinary iodine and TVOL, respectively(r = 0.999 and-0.997, P < 0.05). The iodine intake in processed foods was weakly correlated with the TVOL(r = 0.080, P < 0.01). Non-iodized salt used in processed foods or diets when eating out had less effect on children’s iodine nutrition status.Conclusion Iodized salt remains the primary source of daily iodine intake of SAC, and processed food has less effect on iodine nutrition. Therefore, for children, iodized salt should be a compulsory supplement in their routine diet. 展开更多
关键词 Dining place Source of iodine iodine-rich processed foods Urinary iodine
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Comparison of Thyroglobulin and Thyroid Function in Pregnant Women between Counties with a Median Urinary Iodine Concentration of 100-149 μg/L and 150-249 μg/L 被引量:1
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作者 CHEN Di Qun YE Ying +7 位作者 WU Jia Ni LAN Ying WANG Mu Hua WU Xiao Yan HE Meng WANG Li Jin ZHENG Xin Yi CHEN Zhi Hui 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2023年第10期917-929,共13页
Objective This study explored whether thyroglobulin and thyroid disease prevalence rates were higher in pregnant Chinese women with a median urinary iodine concentration of 100-149μg/L,compared with those with a medi... Objective This study explored whether thyroglobulin and thyroid disease prevalence rates were higher in pregnant Chinese women with a median urinary iodine concentration of 100-149μg/L,compared with those with a median urinary iodine concentration of 150-249μg/L maintained through sustainable universal salt iodization.Methods This was a cross-sectional study in which 812 healthy pregnant women were enrolled to collect samples of their household edible salt,urine,and blood during their routine antenatal care in the18 counties in Fujian Province,China.The levels of salt iodine concentration,urinary iodine concentration(UIC),free triiodothyronine(FT3),free thyroid hormone(FT4),thyroid-stimulating hormone(TSH),thyroglobulin(Tg),thyroid peroxidase antibody and thyroglobulin antibody were assessed during the routine antenatal care visits.Results The median UIC(m UIC)in pregnant women was 130.8μg/L(interquartile range=91.5-198.1μg/L)in the counties with an m UIC of 100-149μg/L(Group I),and 172.0μg/L(interquartile range=123.5-244.4μg/L)in the counties with an m UIC of 150-249μg/L(Group II).Goiter prevalence and thyroid nodule detection rates showed no difference between Group I and Group II(P>0.05).Except for FT4 values,the TSH,FT4,FT3,Tg and Tg values>40(μg/L)and the thyroid diseases prevalence rate(TDR)showed no significant differences between Group I and Group II(P>0.05),whether or not iodine supplementation measures were taken.Conclusion Compared with an m UIC of 150-249μg/L,not only there was no difference in thyroid morphology,but also the Tg value,rate of Tg values>40μg/L,and TDR were not higher in pregnant women in the counties with an m UIC of 100-149μg/L achieved through sustainable universal salt iodization in Fujian Province,China. 展开更多
关键词 Pregnant women Urinary iodine concentration THYROGLOBULIN Thyroid dysfunction
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Development of High Areal Capacity Electrolytic MnO_(2)-Zn Battery via an Iodine Mediator 被引量:2
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作者 Xinhua Zheng Ruihao Luo +9 位作者 Touqeer Ahmad Jifei Sun Shuang Liu Na Chen Mingming Wang Yuan Yuan Mingyan Chuai Yan Xu Taoli Jiang Wei Chen 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第6期243-250,共8页
The commercialization of electrolytic MnO_(2)-Zn batteries is highly applauded owing to the advantages of cost-effectiveness,high safety,high energy density,and durable working performance.However,due to the low rever... The commercialization of electrolytic MnO_(2)-Zn batteries is highly applauded owing to the advantages of cost-effectiveness,high safety,high energy density,and durable working performance.However,due to the low reversibility of the cathode MnO_(2)/Mn^(2+)chemistry at high areal capacities and the severe Zn anode corrosion,the practical application of MnO_(2)-Zn batteries is hampered by inadequate lifespan.Leveraging the full advantage of an iodine redox mediator,here we design a highly rechargeable electrolytic MnO_(2)-Zn battery with a high areal capacity.The MnO_(2)-Zn battery coupled with an iodine mediator in a mild electrolyte shows a high discharge voltage of 1.85 V and a robust areal capacity of 10 mAh cm^(-2)under a substantial discharge current density of 160 mA cm^(-2).The MnO_(2)/I_(2)-Zn battery with an areal capacity of 10 mAh cm^(-2)exhibits prolonged stability of over 950 cycles under a high-capacity retention of~94%.The scaled-up MnO_(2)/I_(2)-Zn battery reveals a stable cycle life under a cell capacity of~600 mAh.Moreover,our constructed MnO_(2)/I_(2)-Zn battery demonstrates a practical energy density of~37 Wh kg^(-1)and a competitive energy cost of<18 US$kWh^(-1)by taking into account the cathode,anode,and electrolyte.The MnO_(2)/I_(2)-Zn battery,with its remarkable reversibility and reasonable energy density,enlightens a new arena of large-scale energy storage devices. 展开更多
关键词 high areal capacity iodine redox mediator large-scale energy storage MnO2-Zn battery
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Electrochemically Generated Iodine Cations from a Glassy Carbon Electrode for Highly Selective Iodination of Anisole
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作者 Liang Yan Haitao Lei +1 位作者 Pengcheng Yang Wei Zhang 《Transactions of Tianjin University》 EI CAS 2022年第6期433-439,共7页
The synthesis of aryl iodides from commercially available raw chemicals by simple,cheap and green strategies is of fundamental signifi cance.Aryl iodides can undergo a series of homo-/cross-coupling reactions for the ... The synthesis of aryl iodides from commercially available raw chemicals by simple,cheap and green strategies is of fundamental signifi cance.Aryl iodides can undergo a series of homo-/cross-coupling reactions for the synthesis of important industrial chemicals and materials.Traditional methods require the electrophilic substitution on aromatic compounds by iodine or hypervalent iodine compounds,which suff ers from the use of erosive halogens or hazardous oxidants.With the development of green chemistry in the fi eld of electrochemical synthesis,anodic oxidation-derived I^(+)cations have been used for substitution reactions.However,the selectivity of the iodination by these electrochemical methods remains unsatisfactory.We believed that the anolyte is contaminated by trace platinum species from the working electrode.Herein,we report the generation of active I^(+)species from the anodic oxidation of I_(2) in acetonitrile using a glassy carbon electrode.With the presence of H^(+),electrolyte prepared with a glassy carbon anode can react with anisole to selectively form 4-iodoanisole with a yield as high as 97%.On contrast,the electrolytes prepared from Pt and graphite anodes fi nished the reaction with yields of 16%and 60%for 4-iodoanisole,respectively.This electrochemical method also applies to the iodination of toluene,benzonitrile and bromobenzene,delivering the target para-iodination products with 92%,84%,and 73%yields,respectively.Thus,an atom-effi cient and highly selective aryl iodination method was developed without the use of excessive oxidants. 展开更多
关键词 iodination ELECTROCHEMISTRY Anodic oxidation Aryl iodides SELECTIVITY
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基于过硫酸钠氧化的烯丙位C-H键官能团化的研究
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作者 杨彩云 张舒婷 +6 位作者 白露露 徐晴 潘庚辰 魏玮 潘馨慧 刘青广 王金辉 《广州化工》 CAS 2023年第5期67-70,80,共5页
设计一种Na_(2)S_(2)O_(8)与金属Cu^(2+)和Co^(2+)催化氧化的交叉脱氢偶联反应,从而实现烯丙位C-H键官能团化的新方法。研究发现,以0.2当量CuSO 4和0.1当量CoCl 2为催化剂,2.0当量Na_(2)S_(2)O_(8)为氧化剂,乙腈为溶剂,80℃下进行环己... 设计一种Na_(2)S_(2)O_(8)与金属Cu^(2+)和Co^(2+)催化氧化的交叉脱氢偶联反应,从而实现烯丙位C-H键官能团化的新方法。研究发现,以0.2当量CuSO 4和0.1当量CoCl 2为催化剂,2.0当量Na_(2)S_(2)O_(8)为氧化剂,乙腈为溶剂,80℃下进行环己烯与乙酰丙酮的交叉脱氢偶联反应,可以实现环己烯烯丙位C-H键的直接官能团化,此方法也适用于与环己烯和乙酰丙酮相似结构的化合物,产率41%~56%。该方法成本低、毒性小、操作简单且易于实现烯丙位C-H键的直接官能团化,具有底物及亲核试剂应用的广泛性。 展开更多
关键词 过硫酸钠 烯丙位c-h键活化 交叉脱氢偶联反应
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